<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<input type="text" id="v1"/>+
<input type="text" id="v2"/>
<input type="button" value="=" id="btn"/>
<input type="text" id="res"/>
<script src="./dist/build.js"></script>
</body>
</html>